The long-term goal of this project is to develop knowledge and techniques to prevent or abort rabies disease by well-defined post-exposure means. In the present study, small animal laboratory models and in vitro cell culture systems are being used to determine the immunologic and virologic parameters most closely associated with either resistance to infection or disease production. In the coming year, the immunologic response of mice vaccinated with a non-virulent vaccine will be compared with the immunologic response of mice given street rabies. The following in vitro tests will be used for this comparison: 1. Cellular cytotoxicity studies (direct type) will be conducted using immune cells from mice and infected neuroblastone cells as the target cell. 2. The lymphoid cell population of mice will be tested for antibody dependent cellular cytotoxicity. 3. Immune lymphoid cells will be tested for reactivity in a model of indirect cellular cytoxicity. 4. The immunologic responsiveness of mice infected with a vaccine strain of rabies will be compared to the responsiveness of mice infected with street rabies using blast transformation tests. Since neuroblastoma cells are readily infected with street rabies in contrast to most epithelial and/or fibroblast cells, the viral receptors on neuroblastoma cells will be characterized.